Abstract: Objective: To analyze the impact of preoperative non-Mechanical Bowel Preparation on patients undergoing Coronary Artery Bypass Grafting (CABG), to providing a reference for the selection of preoperative bowel preparation regimens in cardiac surgery. Methods: A prospective randomized controlled trial was conducted from July to December 2024, enrolling 193 patients scheduled for CABG in a tertiary grade A hospital in Tianjin by convenience sampling. They were randomly divided into a control group (n=96) and an observation group (n=97). The control group received a routine nursing measures with Mechanical Bowel Preparation on the day before surgery, while the observation group only received routine nursing measures without Mechanical Bowel Preparation on the day before surgery. The differences between the two groups were observed in terms of the rate of spontaneous defecation, the time to first spontaneous defecation and the incidence of abdominal pain and distension within 3 days after surgery, and the incidence of intraoperative involuntary defecation. Results: There were no statistically significant differences in the rate of spontaneous defecation and the incidence of abdominal pain and distension within 3 days after surgery, and the incidence of intraoperative involuntary defecation. The spontaneous defecation time within 3 days after surgery in the observation group was (51.15±17.09) h, which was shorter than that in the control group [(65.25±10.25) h] (P=0.029). Conclusion: Without routine Mechanical Bowel Preparation before CABG does not increase the risk of intraoperative involuntary defecation or postoperative abdominal pain and distension. It can improve patient comfort, reduce hospitalization costs, and save medical resources, thereby providing a basis for further standardizing the preoperative intestinal preparation process for patients undergoing CABG.

Key words: Mechanical Bowel Preparation; Coronary Artery Bypass Grafting; patient safety; randomized controlled trial